1. Field of the Invention
The present invention relates to speaker devices to be used with video equipment such as a display monitor, television, and personal computer and, more specifically, to a video equipment speaker device with an acoustic lens.
2. Description of the Background Art
Speaker devices are often equipped with an acoustic lens. The acoustic lens is used for setting a directivity of a speaker device to a desired direction. Conventionally, the acoustic lens for the speaker device is implemented by a plurality of fins. Such speaker device is exemplarily disclosed in Japanese Patent Laid-open No. 6-35489 (1994-35489).
FIG. 14 is a perspective view of a television equipped with television speaker devices having acoustic lenses. In FIG. 14, the television includes a television box 11, a Braun tube 10 provided on the center front of the television box 11, right-channel and left-channel speaker parts 12 provided on the upper-right, upper-left, lower-right, and lower-left portions on the front of the television box 11, center channel speaker parts 13 provided in the vicinity of the upper-center and lower-center on the front of the television box 11, and a plurality of acoustic lens fins 5 provided on the front of the television box 11 and forward of the speaker parts.
However, the structure of such a conventional acoustic-lens-equipped television speaker device poses some problems as follows. First, the complicated fin structure worsens the appearance of the speaker device. Second, each speaker part provided rearward of the fins is almost completely visible to a television viewer, and therefore, the entire appearance of the speaker device may be worsened. Lastly, a sound directivity is ensured only in the direction to which the fins are oriented, and thus is less spread out. If the speaker parts are arranged only on the upper or lower portion on the front of the television box, the reproduced acoustic image will be directed only to the upper or lower side of the television box.
Therefore, an object of the present invention is to provide a video equipment speaker device capable of, even if arranged only on the upper-front or lower-front of the video equipment, directing the acoustic image to the center on the front of the screen, and lending itself to being invisible to a viewer.
A first aspect of the present invention is directed to a video equipment speaker device having an acoustic lens, comprising: a speaker for forwardly outputting sound; a speaker baffle provided forward of the speaker with an opening through which the outputted sound passes; and a fin, as the acoustic lens, opposed to the speaker so as to form slots for sound passage with the speaker baffle. The fin has a shape in cross section such that a central portion of a surface opposed to the speaker is rearwardly curved, wherein the sound outputted from the speaker passes through the opening and reflects between the fin and the speaker baffle to be externally outputted from the slots.
As described above, in the first aspect, the acoustic lens itself is invisible from a viewer of the video equipment. Therefore, the speaker device can be provided without its appearance worsened. Further, with the narrow slots, a sound source becomes analogous to a simple sound source, and therefore, the directivity can be broadened.
According to a second aspect, in the first aspect, the fin has a shape so that the opening of the speaker baffle is not entirely covered when viewed from the front of the video equipment.
As described above, in the second aspect, sufficient sound volume can be maintained while sound pressure is not reduced by the fin. Further, with the narrow slots, the sound source becomes analogous to a simple sound source, and therefore, the directivity can be broadened.
According to a third aspect, in the second aspect, the fin is provided at a position that avoids intersecting with a central axis for sound outputted from the speaker.
As described above, in the third aspect, part of the sound outputted from the central portion of the speaker is not interfered with by the fin. Therefore, since the sound of high-range frequencies is directly outputted from the opening, the sound of the entire range can be outputted with high-frequency characteristics of the speaker unchanged.
According to a fourth aspect, in the third aspect, the central axis passes through one of the slots formed between the fin and the speaker baffle, and part of the sound outputted from the speaker is directly outputted from the slot.
As described above, in the fourth aspect, the sound of high-range frequencies outputted from the central portion of the speaker is directly outputted from the slot. Therefore, the sound of high-range frequencies, which is high in directivity, can be outputted without being obstructed by the fin, allowing high-frequency characteristics of the speaker to be unchanged.
According to a fifth aspect, in the first aspect, the fin is of a rectangular shape when viewed from the front of the video equipment.
As described above, in the fifth aspect, the fin is of a rectangular shape. The fin can thus be positioned along each side of the front of the video equipment. Therefore, the directivity can be broadened without the appearance of the speaker device being worsened.
According to a sixth aspect, in the first aspect, the fin has one or more apertures, and part of the sound outputted from the speaker is externally outputted through the apertures.
As described above, in the sixth aspect, the fin has one or more apertures. Therefore, the sound of high and mid-range frequencies, especially high-range frequencies, can be sufficiently reproduced.
According to a seventh aspect, in the first aspect, a total area of the slots between the fin and the speaker baffle that correspond to the opening of the speaker baffle is approximately equal to an area of the opening rearward of the speaker baffle.
As described above, in the seventh aspect, the total area of the slots between the fin and the speaker baffle that correspond to the opening of the speaker baffle is approximately equal to the area of the opening rearward of the speaker baffle, thereby extremely reducing acoustic resistance. Therefore, the acoustic characteristics and phase can be stabilized, and especially, the acoustic characteristics in high-range and mid-range frequencies can be improved.
According to an eighth aspect, in the first aspect, the central portion of the rearwardly-curved surface of the fin is positioned closer to the speaker through the opening of the speaker baffle.
As described above, in the eighth aspect, acoustic resistance toward the opening is equalized. Therefore, the acoustic characteristics and phase can be stabilized. Also, as the opening is narrower, the sound source becomes analogous to a simple sound source, thereby broadening the directivity.
According to a ninth aspect, in the first aspect, the speaker device is provided on an upper-front and/or lower-front of the video equipment.
As described above, in the ninth aspect, broad directivity can be obtained in both horizontal and vertical directions even when speakers are provided on either an upper-front or lower-front, or both, of the video equipment.
According to a tenth aspect, in the first aspect, the speaker devices are provided on a front-right and front-left of the video equipment.
As described above, in the tenth aspect, broad directivity can be achieved in the horizontal direction if the speakers are provided on the front-right and front-left of the video equipment.
According to an eleventh aspect, in the first aspect, the speaker devices are provided on an upper-front and/or lower-front and a front-right and front-left of the video equipment.
As described above, in the eleventh aspect, the acoustic image can be easily directed to the central portion frontward of the screen even if the speakers are provided on either the upper-front or lower-front of the video equipment. Furthermore, with the speakers provided on the front-right and front-left of the video equipment, broadened directivity in the horizontal direction can be obtained. Therefore, a listener can feel the sound spreading more.
According to a twelfth aspect, in the eleventh aspect, the speaker devices provided on the front-right and front-left of the video equipment are specifically used for high-range frequencies.
As described above, in the twelfth aspect, the acoustic image can be easily directed, at low costs, to the center-front portion forward of the screen even if the speakers are provided on either the upper-front or lower-front of the video equipment. Furthermore, with the speakers provided on the front-right and front-left of the video equipment, broadened directivity in high-range frequencies in the horizontal direction can be obtained. Therefore, a listener can feel the sound spreading more.
A thirteenth aspect is directed to a video unit comprising a video unit box that accommodates a video unit circuit set, first speaker devices provided on an upper-front and/or lower-front of the video unit box, and second speaker devices provided on a front-right and front-left of the video unit box and specifically used for high-range frequencies. Each of the first speaker devices comprises: a speaker for forwardly outputting sound; a speaker baffle provided forwardly of the speaker with an opening through which the outputted sound passes; and a fin opposed to the speaker so as to form slots, for sound passage, with the speaker baffle. The fin has a shape in cross section such that a central portion of a surface opposed to the speaker is rearwardly curved, wherein the sound outputted from the speaker passes through the opening and reflects between the fin and the speaker baffle to be externally outputted from the slots.
As described above, in the thirteenth aspect, the right and left sides on the front surface of the video unit box can be visually simplified, compared to the case in which speaker devices with a fin are provided on a front-right and front-left thereof. Further, the acoustic image can be easily directed, at low costs, to the center-front portion forward of the screen even if the speakers are provided on either the upper-front or lower-front of the video equipment. Furthermore, with the speakers provided on the front-right and front-left of the video equipment, broadened directivity in high-range frequencies in the horizontal direction can be obtained. Therefore, a listener can feel the sound spreading more.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.